Dental mandrel



J. H. ABBOTT.

DENTAL'MANDBEL.

APPLICATION manna. 28, 1919.

'1 ,333,054. Patented Mar. 9,1920.

FIGi

INVENTOI? momvn.

. JAMES HERMAN ABBO T,orrniLADE rrrIA, PENNSYLVANIA.

' DE TAL iviaimrmn 7 '1 '0 all whom it may concern:

Be it known that I, JAMES'IIERMAN AB-'1 so'r'r, a citizen of the United States, and'a resident of Philadelphia, in the county'of.

Philadelphia and State of Pennsylvania,

have invented an Improvement in Dental Mandrels, of which the following is a" specification. v

' My invention has for one of its OlOJQCCS to provide a dental mandrel comprising neans,

the presence of which enables i'grinding disks, disk brushes and otherflike members to be securely fastened so that they willnot rotate relatively to their fasteningmeans or relatively to the mandrel when in use. f

- It is also an object of myinvention to provide {a construction of dental mandrel the employment of which renders agrind 'ing disk which mav be secured thereon more efficient in operation than heretofore, and

also prevents. the uneven wearing away thereof. a 1 A further ob]ect of my inventlon is to I provide; a mandrel with means whereby the grinding member secured thereon is slightly yieldingly supported and heldi Other'objects and advantages offmy invention will be pointed out in. the detailed 7 description thereof which follows or will be apparent from such description.

In order that my mvention may be readily understood and its practical advantages more fully appreciated, reference may be P had to the accompanying drawing in which I have illustrated one form of'a'conv'en-ie'nt embodiment thereof. It will beundel'stood, however, that changesin the detailsof construction may be madewithin thescopeof 7 the claims without"departingffrom'my in vention. In the drawing:

5 mandrel'constructed in accordance 'withmy F invention and having; attached thereto a 45 grinding disk;

Fig. 2 is a view partly in side'elevation Specification or Letters Patent.-

Figure 1 is a side elevation of a dental Patented Mar. 9 192 0.

Application filed February 28,1919, Serial'No. 279,750. 1 r

curing and retaining a grinding, disk 4. or

other. like member in place. It will be-under stood that there may be substituted for the grinding disk a disk brush or other polishing member'such by dentists. I

as are in common'use 5 designates ametal spring, one end ofwhich extends through an opening 6 through themandrel body 1, which opening is 10- cated a distance'belo-w or-beyond theinner end of the longitudinal screw threaded opening 2. In constructing the mandrel, the

end portion of the wire which is to be inserted into the, opening 6 is tapered or re-.

duced and is then inserted. Thereafter the y Y wire is coiled around the upper or outer end portion ofthe'mandrel body as shown inthe drawing, the coils terminating ashort dlstance, usually about two coils, beyond the end of the mandrel body-or stem as is clearly shown in the drawing. In this coiled wire, I

the coils. or-turns' should be close together,

although not directly andffirmlvincontact.

As constructed the coilsof the wireare so close together that with the nakedeye of usual strength'and clearness the spaces be tween the coils are notdiscernible, but b'ythe employment of a magnifying glass it is ap;

parent that the coils'jare notdirectly in contact. It is desirable, although not absolutely essential, that the coils should I be slightly separatediin order that there may be a certain amount of resilience orgive in the coiled w1re .dur1ng the operation of the mandrel in'use. If the coils were in' actual rigidcontact there would perhaps be noapapreciable give or resilien'tjeffect, and certain of the advantages which are -found to be present in .a mandrel. constructed infaccordance with my, invention would not be present'or apparent.

The 'grinding disk 4 or other member,

such as above-suggested,iis-held in place by the head 'of thefscrew with its inner side in contact with-the outer 'end'of the coiled spring 5. Such-outer :end is squared in any suitable manner asindica'tedin the drawingso as to form a firm, smoothseat for the adjacent contacting side of the grinding disk or other like member.

In the use of mandrels as heretofore 0011-.

structed in which a mandrel body is em ,ployed without the presence of a coiled spring such as 5,'the grinding disk such as 4 or other member is seated directly against the end of such body and is held in such "position by means of a screwisuchjas, 3.

However, .it is found that not infrequently such grinding disk or other similar member is not so securely heldbut that it will roe tate relatively to the mandrel and-to theattaching means. I have found that in a mandrel embodying my invention in which the disk or other like member is seated and held against coiled spring as described this does not occur because the spring coacting' with the attaching means,

seems to have a tendency to grip and hold thegrinding disk or' other like membenso that itis held firmly against rotatioirwith respect to the mandrel or to the attach ng means.

It is a known tactthat in the employment [of rindin disks suchas that shown inthe di'awingl it will happen that the peripheral grindlng edges thereof Wlll wear away uncvenly leaving a pro ect1on here or a mo.

jectionthere. hen this condition occurs V and it is attempted to use the grinding disk such PI'QJBCtlOIlS seem to strike the tooth sur i, 'i isyin' r c c c o asea face WlllOl be g g ounl tnl t c u sort of bouncing or bounding inovclnentot' V he mandrel with the result that the operamy invention are I worn away, evenly and 'tion is unsatisfactory and the cutting action of the disk slow because of such bouncing movement or. lateral vibratlon. I have found'that a mandrel. constructed 1n accordance with my invention avoids the oceulu rence of this condition. "For some reason or other the surfaces of the; grinding disks when employed upon a mandrel embodying smoothly. I havealso 'loiuidthat for s me reason or otlleiqia grinding disk nioiulted upon a mandrel constructed in accordance witlr ny invention cutsniore rapidly than does one 'niou-n.ted upon the ordlnary inanjdrel in common use inwhich no springsuch V tiSelIllJlOXfiCl by me 15 present. 7 i v "I. have been unable to determine with jdefiniteness the exact reason or cause for such improvement-in the efficiency of the virtue of the combine: 7 I g ditional weight and the-fact that the grinddevice, It may be by reason ofthe .addi- 'tional Weightof the spring or 1t may heby 1 presence of such. ad;

ing diskis slightly yiel;d ingly.. supported.

Although I have suggested certain poss ble causes lor the increased efliclencyoi and for the-results accomplished by my lnven" tion, iitis to be understood that iny i-nven tion 1s notto be limited lIIfltS" extent or scope byreason'of such reference.

the en, of said 1'od.-= 7

' The term grinding disk when employed n the clanns 1S intendedto-comprehend and include not on ly a disk-like that shown in the drawing, but otherf disksflof like character, such as disk brushes, employed by dentists. I i V 1 c I I claim: r

I 1. A dental. mandrel COlIlPl'iSlllg a body portion provided with a coiled spring member extending beyond said body 'portlon, means lor, preventing rotation of said coiled 7 spring upon said body po'rtionpand means for securing a .dis'k in contact with the eX- tended portion of said spring member. 7

2. A dental mandrel comprising a rod, :1

wire connected at one end to the said rod a.

distance from one end of the latter. and coiled from its point of connection around the said rod; said coil extending to a point beyond the end of said rod, and means for securing a disk in Contact with the outer end portion of said coiled wire. 3. A den-tal'niandiel comprising a rod thereof, a wire connectedwith the said 111andlicl and coiled aroundlthe end portion thereof which is provided with the said opening thesald coiled wn-e extending a short distance beyond the end of the .sald rod, and

means adapted to engage thesaid screw I730 having a screwthreaded opening 111 one end coilsof said spring being in close proximity to: each 1 other and said spring terniina ting ap roxnna-tely a couple of coils beyond o. Ina dental mandrelfthe combination of a mandrel stein or.body, a grinding disk,

resilient rnie'a-ns interposed between said grinding disk [and said steln -o1 body, the said grinding disk being seated against the said means and being out of contact witl'i. the said stem or bodygand means for attachiug the said grinding disk to the said stein or body and tor clamping and holding the same against the said: resilient means; sub- 1 stantially as described, I In testimony that I Clftll11tl16 foregoing as my invention Ihave hereunto set my name 7 this 25th day of February, A. l9l9.

JAMES HERMAN ABBOTT. 

